Ultraviolet filter on photographic layers



I. F. SALMINEN ETAL 2,632,701

ULTRAVIOLET FILTER ON PHOTOGRAPHIC LAYERS March 24, 1953 Filed May 4, 1949 YELLOW DYE WAGE /v LAYER CONTAIN/N6 SULFON/C ACID SALT 0F I3 DISAL/CYL BENZlD/DE MAGENTA DYE IMAGE 11 AN DYE IMAGE SUPPORT IlmariESalminen CharlesEIiAllen IN VEN TORS ATTORNEY S Patented Mar. 24, 1953 ULTRAVIOLET FIL'EER ON PHOTOGRAPHIC LAYERS Ilmari F. Salminen and Charles F. H. Allen, Rochester, N. Y., assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of NewJzerscy Application May 4,1949, Serial No. 91,422

4r Claims;

This invention relatesto a method of protecting multi-layer photographic elements against the action of ultra-violet light and to multi-layer elements containing ultra-violet filtering materials.

It is known that color photographs on multi layer photographic material, particularly where the dye images are formed in sensitive emulsion layers by color development, are susceptible to fading and discoloration by the action of ultraviolet light to which the photographs are subjected during viewing. It is also known that the residual couplers contained in the emulsion layers after formation of the picture images in certain processes, are attacked by ultra-violet light and form a stain which is undesirable in the finished photograph. The action of ultra-violet light on finished color photographs is particularly noticeable in positive prints on paper or other opaque supports since this type of print is frequently viewed in daylight where there is a, high content of ultra-violet radiation.

It is also known that color photographs, especially where the dye imagesare formed by color development, can be protected from the fading and discoloration caused by ultra-violet light by applying to the finished color photograph a layer of gelatin or other colloidal material having therein an ultra-violet asborbing material. A process of this type in which aesculin, quinine, primuline, disalicylbenzidide, etc., are used as ultra-violet absorbing materials in a gelatin overcoating layer is described in British Patent 565,929. Processes of this type have the objection that the ultra-violet filtering material must be applied from colloidal solution, e. g., gelatin, and an application of this character requires coating machinery and necessitates an expensive and additional coating operation after the processing of the color print is finished.

It is therefore an object of thepresent invention to provide a simple method for protecting finished multi-layer photographic color prints against the action of ultra-violet light. A fur ther object is to provide finished multi-layer color photographs in which the color image is not appreciably subject to fading or discoloration by the action of ultraviolet radiation. Other objects will appear from the following descrip tion of our invention.

These objects are accomplished, by applying to the outermost layer ofa multi-layer photographic element, where the outermost layer is gelatin, an aqueous non-colloidal solution of a water-soluble sulfonated organic compound which is adsorbed to gelatin and which'is absorbent of ultra-violet light of wave length between 300 and 400 millimicrons but transmissive of light of wave length longer than 400mi'llimicrons. In particular, we have found that water-soluble sulfonic acid salts of compounds of the following structure are especially useful for application to the finished gelatin layer from non-colloidal solution:

Y-NHR-XR-NHY where X:.-C.H:CH--, or representsa single chemical bond R a mononculear aryl radical :benzoyl or s-triazinyl OH OH.

| V l C -G ONE-@G-NHG 0Q SOzNa SOaNa Disalicylbenzididc sodium sulfonate CONH-OQNHCOQ some some Disalicyltoluidide sodium sulfonate (I) H C|)C Ha (|)C Ha OH I p r Y 7 q S OsNE v S OsNa Disalicyl-di-o-anisidide sodium sulfonatc some OsNa Di- (2-l1ydroxy-4-methylbenzoyl) -benzidide sodium sulfonate CH5 OH OH CH3 0 NEGO-NHC 0 OaNa O 3N3.

Di- (2'-hydroxy-3-methylbenzoyl)benzidide sodium sulfonate HOOC C0011 no-bsomnQOrrnsmO-on Bis-(4-hydroxy-3-carboxyphenyl sulfonyD-benzldide S OaNa 4,5-diphenyl2-imidazolondisulfonic acid (Na salt) came 0 NH-Q-C H=C E-QNHC 000E.

SOaNa S OaNa 4,4-di-(phenylcarbamido)-stilbene-2,2-disulfonic acid (Na salt) on OK E some 40.1% N=(|3 OH OH 4,4-di- 3 5 -dihydroXy-s-triazinylamino -stilbene- 2,2-disulfonic acid (Na salt) These ultra-violet absorbing materials have a high ultra-violet absorption in the regions between 300 and 400 millimicrons but relatively little absorption in the visible region at wave length longer than 400 millimicrons. We prefer to apply them to a multi-layer photographic element such as those described in Mannes and Godowsky U. S. Patent 2,304,940, or Jelley and Vittum 2,322,027, by coating from a simple aqueous solution after the multi-layer element has been developed and fixed. The solution of the ultra-violet absorber may be used as the final stage of the processing of the material described in the U. S. Patents 2,304,940 or 2,322,027, that is, after the final wash but before drying. However, if the multi-layer element has been washed and dried, the ultra-violet absorber may be applied after drying and the photograph again rinsed and dried.

The following example illustrates a method of applying our ultra-violet absorbing material.

After the final washing step of the process described in U. S. Patents 2,304,940 or 2,322,027, the photographic element is treated in the following solution for minutes followed by a 1-minute rinse and finally a squeegeeing operation.

Grams Disalicylbenzidide sodium sulfonate 10 Water to 1 liter.

The pH of the ultra-violet absorber solution is preferably adjusted to 7.0 or 8.0 by the addition of either sodium hydroxide or hydrochloric acid as required. After treatment for about 10 minutes as indicated, the element is dried in the normal manner.

With some of the ultra-violet absorbers, it is desirable to follow the bathing operation by a brief treatment, e. g., two minutes, in an aqueous 4 residual magenta coupler in the multi-layer element on moist storage of the finished print. The acid buffer treatment has nothing to do with the adsorption of the ultra-violet absorber.

It has been found advantageous to incorporate in the uppermost gelatin layer of the multilayer element to which the ultra-violet absorber is applied, a mordant for the ultra-violet absorber. Polyvinyl pyridine methyl p-toluenesulfonate has proven particularly suitable as a mordant for the various sulfonated ultra-violet absorbers which we propose to use. Such a mordant binds the ultra-violet absorber more tightly to the gelatin layer and permits a washing operation after the application of the absorber. By use of this expedient the absorber may be introduced at some tage of the process before the final wash and this obviates the necessity for the acid-bufier treatment described above.

The preparation of disalicylbenzidide sodium sulfonate is illustrated by the following example and other compounds which we propose to use as ultra-violet absorbers may be similarly prepared.

A solution of 40 g. of benzidine, g. of phenyl salicylate and 500 g. of a-chloronaphthalene was heated in a 1-l. flask attached to a 12-inch Vigreux column so that the phenol distilled (-200"). When no more phenol distilled, the reaction mixture was heated strongly until the temperature of the distilling vapours was between 235-240 C., at which point the reaction was considered to be complete. On cooling to room temperature, the product separated. It was collected by filtration and washed with dioxane and then acetone. The yield of light gray product was 88.5 g. (98) M. P. 320-324".

Eighty grams of finely pulverized disalicylbenzidide were added to 480 ml. of concentrated sulfuric acid, and the reaction mixture was maintained at an inside temperature of 88-93 C. for 3.5 hours. It appears as a clear dark brown solution at this point. It was poured with good stirring into 2400 ml. of 10% potassium chloride, using Dry Ice as an internal coolant. After standing for one hour to allow for coagulation, the product was collected by filtration. The filter cake was boiled with l-l. of methanol and again filtered. The crude sulfonic acid thus obtained was taken up in '600 ml. of 10% sodium carbonate solution and decolorized twice, using 15-20 g. portions of Norite, after which 60 g. of sodium chloride was added to the boiling solution with good stirring. The stirring was continued while coo-ling to room temperature and the mixture was then allowed to stand overnight. The crystalline white product was collected by filtration and washed with methanol. The yield was 30 g. The filtrate was heated to boiling and 100 g. of sodium chloride was added with vigorous stirring and treated as before: after filtering and drying 66 g. of product was obtained. The combined yield was 96 g. (80% of the theory of 119 g.)

Our invention will now be described 'by reference to the accompanying drawing. As shown therein a support I0 is coated with superposed layers ll, l2 and I3 containing respectively cyan, magenta and yellow dye images. These are finished photographic layers, that is, developed and fixed emulsions after exposure and color development, and removal of residual silver and silver halide. The outermost layer I3 has on it a layer I4 of gelatin containing the sulfonic acid salt of disalicylbenzidide, the sulfonic acid salt having been applied from an aqueous noncollo-idal solution.

It will be understood that the examples and modifications included herein are illustrative only and that our invention is to be taken as limited only by the scope of the appended claims.

in which X is selected from the class consisting of -CI-I'=CH-- and a single chemical bond, R represents a mononuclear aryl radical and Y is selected from the class consisting of benzoyl and s-triazinyl radicals, said compound being adsorbed to the gelatin and being absorbent of ultra-violet light of wave length between 300 and 400 millimicrons but transmissive of light of wave length longer than 400 millimicrons.

2. The method of applying an ultra-violet pro tective agent to a developed and fixed multi-layer photographic element having superposed dye images and having a gelatin layer as the outermost layer which comprises applying tosaid gelatin layer from aqueous non-colloidal solution, a water-soluble sulfonated disalicylbenzidide which is adsorbed to the gelatin and which is absorbent layer photographic element having superposed dye images and having a gelatin layer as the outermost layer which comprises applying to said gelatin layer from aqueous non-colloidal solution, disalicylbenzidide sodium sulfonate which is adsorbed to the gelatin and which absorbs ultraviolet light but transmits visible light.

of ultra-violet light of wave length between 300 and 400 millimicrons but transmissive of light of wave length longer than 400 millimicrons.

3. The method of applying an ultra-violet pro: tective agent to a developed and fixed multi- 4. A finished photographic element comprising a paper support having thereon three superposed developed and fixed gelatin emulsion layers each containing coupled dye images, said dye images being subject to fading by the action of ultraviolet light, an outermost layer of said element being a gelatin layer containing a polyvinyl pyridine mordant and also containing a watersoluble sulfonic acid salt of a disalicylbenzidide which is adsorbed and mordanted to said gelatin and is absorptive of substantially all ultra-violet light of wave length between 300 and 400 millimicrons but transmissive of light of longer wave length than 400 millimicrons.

' ILMARI F. SALMINEN.

CHARLES F. H. ALLEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,568,511 Lehmann Jan. 5, 1926 FOREIGN PATENTS Number Country Date 333,933 Great Britain Aug. 25, 1930 493,308 Great Britain Oct. 6, 1938 524,377 Great Britain Aug. 5, 1940 565,929 Great Britain Dec. 6, 1944 

1. THE METHOD OF APPLYING AN ULTRA-VIOLET PROTECTIVE AGENT TO A DEVELOPED AND FIXED MULTI-LAYER PHOTOGRAPHIC ELEMENT HAVING SUPERPOSED DYE IMAGES AND HAVING A GELATIN LAYER AS THE OUTERMOST LAYER WHICH COMPRISES APPLYING TO SAID GELATIN LAYER FROM AQUEOUS NON-COLLOIDAL SOLUTION, A WATER-SOLUBLE SULFONIC ACID SALT OF A COMPOUND HAVING THE FOLLOWING STRUCTURE: 